[SBE] Hybrid issues.

[Albert Muick]

Curt,

This kinda puts a whole new paintjob in it.

I had the same sort of issue in UN Radio in Haiti.  We were also using Telos
equipment, and had to figure out a way to open up lines to local callers.

Our PABX system was an Ericcson, one of the few digital systems that Telos
doesn't like.  We took the local Telco lines, interfaced them with A/D
converters to the Ericcson and then had to use D/A converters back to the
analog phones and the Telos in the studio.  The result was a whine, and
flanger-like effect, and an echo on SOME live calls.  Enough to make the
call unusable.  The AGC had to be off, and you have to make sure that you're
using the right level input for your line.  We also did a complete alignment
on the Telos unit, making sure it was exactly by the book.

The problem was still there, but greatly minimized.  The other half of the
issue turned out to be the digital audio router/mixer that we were using
called a Yellowtec Intellimix, and was the bane of my existence there.  The
digital output of the Telos was run into one of the mixing ports and brought
up as needed.  When I replaced the Yellowtec beastie with a real piece of
equipment, the problems were unnoticeable.

You might want to look at the downline equipment after the Telos as well.

Good luck!

Al Muick, CBRE
Kabul, Afghanistan

-----Original Message-----
From: sbe-bounces at sbe.org [mailto:sbe-bounces at sbe.org] On Behalf Of Curt
Yengst
Sent: Thursday, January 29, 2009 9:20 PM
To: sbe member discussion mail list
Subject: Re: [SBE] Hybrid issues.

It's a little hard to describe without actually hearing it.  As soon as the
caller starts talking, you hear a very slight "howl" (like feedback) under
them, and in some cases you can also hear their voice echoing under that.
It does have a sort of "comb filter" flavor to it.  It doesn't happen with
every call though.  I was ready to blame it on cell phones, but the jock
claims he's heard it on land lines as well.  Of course, even land lines
these days go through all manner of A/D conversions, delays, and such.
 

________________________________

From: sbe-bounces at sbe.org on behalf of chscherer at everestkc.net
Sent: Thu 1/29/2009 11:19 AM
To: sbe member discussion mail list
Subject: Re: [SBE] Hybrid issues.



Then it's not listener radio delay coming back in.

Feedback and echo are two differnent symptoms. Can you clarify? Feedback
(even comb filtering) would point to a problem in the mix-minus. Echo points
to phone line blead.

----- Original Message -----
From: Curt Yengst <cyengst at star991fm.com>
Date: Thursday, January 29, 2009 10:07 am
Subject: Re: [SBE] Hybrid issues.


> Not sure this is the issue.  Although we don't use a profanity delay 

> (yet), we do delay our analog signal to match up with our HD signal, 

> which creates an on-air delay of about 8 seconds.  This feedback/echo 

> is happening almost instantly (less than half a second).

> ________________________________

>

> From: sbe-bounces at sbe.org on behalf of chscherer at everestkc.net Curt 

> said:

> "One jock claims it only happens on live calls, not on pre- recorded 

> calls."

>

> Is it this simple:

> Are the problem callers not turning their radios off?



> ----- Original Message -----

> From: Chris Tarr <chris at broadcastdoc.net>

> > Curt-

> >

> > I may be reading that wrong, but wouldn't you want "mics only"

> to feed

> > the hybrid?  Not sure what the "hybrid out" feed would do (except 

> > maybe offer an option to send audio form the audition channel

> down the

> > line) but the only thing that should feed the hybrid on a regular 

> > basis is the microphones.  While an echo is indicative of poor 

> > cancellation, it seems like maybe the caller audio is getting

> fed back

> > down the line.




> > On Thu, Jan 29, 2009 at 9:46 AM, Curt Yengst

> > > I'm in the process of troubleshooting a complaint from some of

> > our jocks.

> > > When they take calls on our Telos 2x12, sometimes the call will

> > have a bit

> > > of feedback/echo under the caller.  If the jock pots down the

> > 2x12 output at

> > > the console, it can be somewhat controlled, but then the

> > complaint is that

> > > the caller audio is too low in level (duh!).  It doesn't happen

> > on every

> > > call, but it's enough to irritate them.  We have the Telos 2x12

> > connected to

> > > a Wheatstone D-75 audio console, using their SP-75 "Superphone"

> > input> module, which has its own mix-minus.  It also has the

> > ability to generate

> > > separate outputs for hybrid out, "mics only" out (everything

> but the

> > > caller), and "callers only" out.  We're using the hybrid outs to

> > feed the

> > > 2x12 inputs.  The Caller 1 output of the 2x12 (which gets used

> > almost> exclusively) is split with a Y-cable, with one side going

> > to the caller

> > > input on the Superphone module and the other side going directly

> > to the

> > > caller side of our VoxPro workstation.  One jock claims it only

> > happens on

> > > live calls, not on pre-recorded calls.

> > >

> > > I e-mailed Telos, and the answer was basically that it was a

> > phone company

> > > issue (poor echo cancellation), and since it was coming into the

> > station> sounding that way to begin with, there was nothing we

> > could do about it.

> > > Wheatstone basically said the only way their equipment would

> > possibly> exhibit this issue was if caller conferencing wasn't

> > properly set up.  Since

> > > the problem happens with single callers, this is moot.

> > >

> > > Any thoughts?

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